The present invention relates to a cylinder lock with a pivotally-mounted bolt.
As “cylinder lock” it is meant any lock which can receive a lock cylinder for actuation of said bolt. As “lock cylinder”, it is meant a lock mechanism with a housing having a standard profile, such as the europrofile, the British oval profile, or the Swiss profile, and a cylinder with a radially protruding cylinder cam and a key groove, wherein the cylinder can only be rotated within the standard profile with a key inserted into said key groove if said key has a suitable profile for unlocking said lock mechanism, which can be of any suitable type, such as the pin tumbler type, the wafer tumbler type, or the disc tumbler type.
As “pivotally-mounted bolt” it is meant a bolt pivotally moveable between a retracted position and an extended position. Such a pivotally-mounted bolt has advantages over a translating bolt, such as a potentially bigger cross-section, and thus greater resistance to breakage and a longer reach by reduced space. Moreover, such a pivotally-mounted bolt can take the form of a hooked bolt, which, in said locking position, prevents that the lock and the striker plate receiving the bolt opposite to the lock be forced apart.
European patent EP 940 532 B1 illustrates such a cylinder lock, comprising:
a housing with an opening for receiving a lock cylinder with a radially protruding cam;
a bolt pivotally moveable between an retracted position and an extended position with respect to said housing;
a ring comprising a radial opening for engaging said lock cylinder cam, so as to couple said ring and lock cylinder cam, and a toothed arc with a first end adjacent to said radial opening, and a second end;
a slider, coupled between said pivotally-mounted bolt and said ring and comprising a toothed rack for engaging said toothed arc and a recess adjacent to a first end of said toothed rack for engaging said lock cylinder cam, wherein said housing presents a guide for guiding said slider between a first position holding the bolt in said retracted position and a second position holding the bolt in said extended position.
A drawback of this prior art is that the slider is not reliably retained when the bolt is in its extended position. As a result, the slider forms a vulnerable point in the lock which could potentially be exploited with malicious intent. In this prior art cylinder lock, a number of security measures are proposed to neutralise this vulnerability, notably a movable fulcrum for the pivotally-mounted bolt. However, these security measures are complex and costly, and add additional potential sources of failure.
Another drawback of the abovementioned prior art is that the slider is not reliably retained when the bolt is in its retracted position. As a result, the slider may move out of correct engagement with the ring, in particular when the lock is shipped without a lock cylinder. This can then complicate the correct assembly and installation of the lock. It is a first object of the invention to maintain the correct position of the slider when the bolt is extended and/or when the bolt is retracted, so as to ensure the reliability, and security of the cylinder lock.